1. Field of the Invention
This invention relates generally to a multiple display system, and more particularly to such a multiple display system for displaying a VIDEOTEX information.
2. Description of the Prior Art
Recently, a multi-screen system is often used in department stores, shopping centers, concourses in stations, sites for exhibition and so on, to attract many people. The multi-screen system for this purpose is generally constructed such that a digitizer, a plurality of VTRs, video disk players and so on are used to fetch a single analog video signal, convert the analog signal into a digital signal, convert again the digital signal into a plurality of analog video signals, to thereby supply the analog video signal to a plurality of displays, respectively.
However, the above-mentioned prior art system requires plurality of VTRs and video disk players and particularly an expensive digitizer so that the production cost thereof is high. Further, when the information displayed on the screen of the displayer is to be renewed or changed, new information must be newly recorded by a video tape recorder, edited, processed and so on so that it takes much time for preparation.
On the other hand, the recently spreading VIDEOTEX system has its video information standard unified by the VIDEOTEX protocol. Thus, it is easy to obtain a number of or variety of video information. Then, if the information is displayed by the multi-screen system, it is possible to attract many people.
However, the video signal used in the VIDEOTEX system is a coded signal which cannot be so easily edited as the above-mentioned analog video signal.
Further, in the multi-screen system, the original video signal is required to be divided into the same number as that of display devices, which results in a complicated construction of the system.
Further, if an enlarged picture is produced by a plurality of display devices, discrepancies occur at the edges between adjacent display devices, so that the resulting displayed picture becomes apt to be one with parts unnaturally linked. Furthermore, it is difficult to display a plurality of pictures in synchronism with each other. Particularly in the case where blinkings occur over a plurality of display areas, it is more difficult to establish the synchronization among the blinkings.
Also, let be assumed that video information is divided as above at a control center and the video signals so divided are transmitted to respective terminal devices, each of which is connected to each of the display devices. If in this case, a plurality of the terminal devices are connected in parallel with one another to the control center, it is required to provide each of the terminal devices with a transmission port and prepare transmission lines to connect the control center with each of the terminal devices, which results in complicated control program and circuit construction and also the high production cost.